A simplicial sheaf is equivalently
in a category of sheaves for some site ;
that satisfies degreewise the sheaf condition;
which, when regarded under the equivalence
is degreewise a sheaf.
The Jardine local model structure on simplicial presheaves restricts to the standard model structure on simplicial sheaves. This restriction is a Quillen equivalence, so that equipped with this model structure is a model for the hypercomplete (infinity,1)-topos over the site .
Historically, Joyal constructed his model structure on simplicial sheaves first and Jardine later constructed his model structure on simplicial presheaves.
Blandner proved that the category of simplicial sheaves admits a model structure whose weak equivalences are the same as in the Joyal model structure and acyclic fibrations are the projective (i.e., degreewise) acyclic fibrations.
The original construction due to Joyal in 1984 is in
Discussion of the homotopy theory of simplicial objects in toposes using Cisinski model structures:
The last part of
is announced to be about simplicial objects in toposes, but that part does not exist yet.
For more see at simplicial presheaf and model structure on simplicial presheaves.
Last revised on July 27, 2024 at 13:13:23. See the history of this page for a list of all contributions to it.